The 1979 Soviet invasion of Afghanistan spurred Jimmy Carter to issue an ultimatum on January 20, 1980 that the United States would boycott the Moscow Olympics if Soviet troops did not withdraw from Afghanistan within one month.[2] After an April 24 meeting, United States Olympic Committee (USOC) President Robert Kane told the International Olympic Committee (IOC) that the USOC would be willing to send a team to Moscow if there were a “spectacular change in the international situation”.[3]

Lord Killanin, then president of the IOC, arranged to meet and discuss with Jimmy Carter and Soviet General SecretaryLeonid Brezhnev, before the May 24 deadline, the boycott in an attempt to save the Games. Lord Killanin insisted that the Games should continue as scheduled, and Carter reaffirmed the US position to boycott unless the USSR withdrew from Afghanistan.[4]

Several interventions at the late April 1980 Bilderberg meeting in Aachen included discussion of the implications of the boycott. There was a heavy contention voiced that the perception to the world of the boycott would be viewed as merely a sentimental protest rather than a strategic act. An African representative at the Bilderberg meeting believed that regardless whether there was additional support outside the US a boycott would be an effective symbolic protest dramatically visible to those within the Soviet Union.[5] The Carter administration brought immense pressure on the NATO countries to support the boycott although that support was not universal.

The International Olympics Federations protested that the pressures by the US and other supporting countries for the boycott was an inappropriate means to achieve a political end, and the victims of this action would be the athletes.[6] German Chancellor Helmut Schmidt said that the allies "should simply do as they are told".[7] Boxer Muhammad Ali was dispatched by the administration to Tanzania, Nigeria, and Senegal to convince its leaders to join the boycott, although it was widely said in the US domestic press that the reactions to Ali's public comments in Tanzania supported the that the diplomatic mission was a failure.[8]

The United States was ultimately joined fully in the boycott by some countries — including Japan, West Germany (Schmidt was able to convince its National Olympic Committee (NOC) to support the boycott by a narrow margin), China, the Philippines, Argentina and Canada. Some of these countries competed at the Olympic Boycott Games in Philadelphia. The governments of United Kingdom, France and Australia supported the boycott but left any final decision for their athletes to participate in the Games to their respective NOC's and the decision of their individual athletes. The United Kingdom and France sent a much smaller athletic delegation than what was originally possible. The British associations that governed equestrian, hockey, and yachting boycotted completely.[9] Despite the national boycotts, the United Kingdom sent the largest team of 170 athletes among West European countries.[10]

Spain, Italy, Sweden, Iceland and Finland were other principal nations representing western Europe at the Games, [10] but those Italian athletes serving in its military corps could not attend the Games because of the national government's official support of the boycott. Many events were affected by the loss of participants and some US-born athletes but citizens of other countries, such as Italy and Australia, did compete in Moscow.

Many teams were avoided by Soviet television at the Games during the opening and closing ceremonies because their national governments officially supported the boycott. Their national colors could not be flown or anthems not played (Australia, Andorra, Belgium, Denmark, France, United Kingdom, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Puerto Rico, San Marino, Spain, and Switzerland).

Lord Killanin permitted NOC-qualified athletes to compete at the Games without their national flags or anthems (which allowed NOCs to send athletes in a non-national context) but this did not allow other individuals lacking NOC sanction to participate in the Games as this was perceived by the IOC as a potential weakening of their authority.[3] Four athletes from New Zealand competed independently and marched under their NOC flag because the government officially supported the boycott.[11] The athletes of 16 countries did not fly their national flags. Instead NOC flags were raised and the Olympic Anthem replaced their national anthems at medal ceremonies. There was one awards ceremony where three NOC flags were raised.

Other modifications in the Games activities were made, such as when the Boycott prevented Montreal Mayor Jean Drapeau from attending the Moscow Games. Sandra Henderson and Stéphane Préfontaine, the final torchbearers at the previous games, were sent in his stead to participate in the Antwerp Ceremony at the opening ceremony, and at the closing ceremony, the Los Angeles city flag (rather than the United States flag) was raised to symbolize the next host of the Olympic Games. The Antwerp flag was received by an IOC member from the USA instead of the then-current Los Angeles mayor, Tom Bradley; there was no handover to Los Angeles ceremony at the closing.

The Moscow Games does have the distinction that with only 80 participating countries there were more world records set than at the fuller contingent attending in 1976 in Montreal.

Sixty-five countries that were invited to participate did not do so in the 1980 Olympics for various reasons such as supporting the boycott or economic reasons. Qatar could not be invited until IOC recognition which occurred in 1980 but too late to be invited.[15]
Chinese Taipei/Taiwan refused to participate as a result of the 1979 Nagoya Resolution, in which the People's Republic of China agreed to participate in IOC activities if the Republic of China was referred to as "Chinese Taipei" .

4 national teams participated at the Games under the Olympic flag rather than their respective National or NOC flags which would denote that their participation was officially sanctioned by their respective nations. [clarification needed]:[16]

The succeeding 1984 Summer Olympics, held in Los Angeles, United States saw another boycott, this time led by the Soviet Union. On May 8, 1980, the Soviet Union issued a statement that the country would boycott the 1984 Summer Olympics in Los Angeles due to "chauvinistic sentiments and an anti-Soviet hysteria being whipped up in the United States".[19] Thirteen Soviet allies joined the boycott, making a total of fourteen nations that boycotted the Olympics. Iran and Albania were the only countries that boycotted both Moscow and Los Angeles. Romania was the only Eastern bloc country that participated in the 1984 Games.